Graft material injector system and method

ABSTRACT

A graft material injector device and method are disclosed. The injector device includes an elongated injector tube and a side loading aperture for receiving graft material. A graft material loader and a cover for the side loading aperture may optionally be included.

This application is a continuation of U.S. patent application Ser. No.16/021,574, filed Jun. 28, 2018, which is a division of U.S. patentapplication Ser. No. 15,018,326, filed on Feb. 8, 2016, now U.S. Pat.No. 10,022,243, which claims priority to and the benefit of U.S.Provisional Application No. 62/112,969, filed Feb. 6, 2015, all of whichare hereby incorporated herein by reference.

FIELD OF THE DISCLOSURE

The present invention pertains to devices for minimally invasiveprocedures in the field of orthopedic surgery and more particularly todeployment of bone graft material into the disc space during a fusionprocedure.

BACKGROUND

A major cause of chronic, and often disabling, back pain is disruptionor degeneration of an intervertebral disc. The spine is comprised ofbony vertebrae separated by intervertebral discs. Each intervertebraldisc connects adjacent vertebrae and forms a form of joint that allowsmovement of the vertebral column. An intervertebral disc is generallydivided into two regions: the nucleus pulposus and the annulus fibrosus.The nucleus pulposus is a gelatinous-like tissue that lies at the centerof the disc and provides a cushion between adjacent vertebrae. Theannulus is made up of collagen fibers that form concentric lamellae thatsurround and contain the nucleus pulposus.

There are many causes of disruption and degeneration of intervertebraldiscs, which can be broadly categorized as mechanical, genetic andbiochemical. Mechanical damage includes herniation in which a portion ofthe nucleus pulposus projects through a fissure or tear in the annulusfibrosus. Genetic and biochemical causes usually result from changes inthe biochemical processes of a disc. Such changes can be attributed togenetic disorders or environmental influences. Degenerative disccondition is commonly caused by a change in the biochemical process ofan intervertebral disc. Such degeneration is a progressive process thatusually begins with a decrease in the ability of the nucleus pulposus toabsorb water. With a loss of water content, the nucleus becomesdehydrated, resulting in a decrease of internal disc hydraulic pressure,and ultimately to a loss of disc height. This loss of disc height cancause the annulus to buckle, eventually resulting in annular fissuresand ruptures. Herniation occurs when a rupture leads to protrusion ofthe nucleus pulposus through the annulus.

Furthermore, disc height plays an important role in the functionality ofthe intervertebral disc and spinal column, and changes in disc heightcan have both local and wider effects. On the local (or cellular) level,decreased disc height may result in increased pressure in the nucleuspulposus, which can lead to a decrease in normal cell operation and anincrease in cell death and disintegration. In addition, increases inintra-discal pressure may create an unfavorable environment for fluidtransfer into the disc, which can cause a further decrease in discheight.

Decreased disc height also results in significant changes in the largermechanical stability of the spine. With decreasing height of the disc,the facet joints bear increasing loads and may undergo hypertrophy anddegeneration. Decreased stiffness of the spinal column and increasedrange of motion resulting from loss of disc height can lead to furtherinstability of the spine, as well as back pain.

Several disc defects may be treated by implantation of a prosthetic intothe nuclear space of the intervertebral disc. Some procedures that mayinclude insertion of a prosthetic into the disc are spinal fusion anddisc repair and replacement. Prior to implantation of most prostheses, adiscectomy is often performed to prepare the nuclear space forimplantation of the prosthetic and, when spinal fusion is desired, tofacilitate bony fusion between the vertebral bodies. Some implantationprocedures may require a total discectomy in which the majority (andusually all) of the volume of the nucleus pulposus is removed. Othersmay require a partial discectomy in which only a portion of the nucleuspulposus is removed.

Traditionally, when a fusion is the desired treatment option, there areseveral approaches to access the disc space and position an implant toregain the proper disc height. For a typical posterior surgicalapproach, an incision is made through the back of a patient and accessto the disc space is achieved. Manual instruments are used and insertedthrough the access to the intervertebral disc requiring treatment. Thecurettes and rongeurs are used to cut, tear, and remove nucleus pulposustissue one piece at a time, and the rasps are utilized to roughen orscrape the endplates of adjacent vertebrae. Other options have beendisclosed previously to provide a more accurate and minimally invasivediscectomy such as disclosure “Disc preparation tools and methods usingthe same” U.S. Application Ser. No. 62/021,960, filed Jul. 8, 2014.

Once the disc has been removed, the implantation of the intervertebralimplant device can be achieved. Such devices and methods have also beenpreviously disclosed in application “Device for treating the Spine” U.S.application Ser. No. 12/035,298, filed Feb. 21, 2008, and moreparticularly, in application “Spinal fusion implants and devices andmethods for deploying such implants” U.S. application Ser. No.13/803,322, filed Mar. 14, 2013 and incorporated by reference herein.

A further component needed in the fusion process to create bony fusionbetween the two vertebral bodies and that is bone graft material or bonefiller material (both of which are generally referred to herein as graftmaterial). Such material will favor the creation of a bony bridge thatspans across the implant and connects the inferior (lower) cartilaginousendplate of the superior (upper) vertebral body to the superior (upper)cartilaginous endplate of the inferior (lower) vertebral body.

Traditionally, the graft material (bone graft material and/or bonefiller material) is positioned into the implant, such as a cage, priorto insertion into the disc space and due to this process cannot be fullyoptimized for best endplate to endplate contact.

In addition, previous graft delivery systems are back-loading, such thatthe graft material must be advanced a great distance through the barrelbefore it is extruded into the delivery site. More work (force appliedover a greater distance) is therefore required to achieve thissuccessfully, and often the nature of the graft material may causesignificant binding when pushed over longer distances, rendering thedevice unusable.

Minimally invasive spinal surgery requires that all surgical tools be assmall as possible to minimize tissue trauma and exposure to the surgicalsite. Tools to deliver bone graft that have a delivery diameter of 10 mmor less are highly susceptible to requiring large forces to deliver thebone graft material or, in the worst case, may seize entirely because ofthe high resistance developed when pushing materials of large, irregulargrain size like autograft bone graft material. This susceptibility toseizing is aggravated by the length over which the graft must bedelivered down the tool, which is typically 6 or more inches if thematerial is loaded at the most proximal tube position and pushed all theway to the delivery site.

Typical bone graft tools incorporate a proximal funnel, a long tubelength, and a manual tamp that requires the user to tap to deliver thegraft to the site. Large bone chips loaded into the tube chamber cancontribute significantly to delivery resistance. To overcome theresistance, the outer diameter of the delivery tube is often quite large(>10 mm). Further, the loading of these long-bored funnels must be doneat the surgical site, lest the material fall out at an undesirablelocation. Thus, this requires the primary surgeon to load and tamp thegraft material into place.

There continues to be a need for further development and advancement inthis field. For instance, in disclosure PCT publication WO 2014/158680(incorporated by reference herein) FIG. 32 shows a cannula that extendsthru the side wall of an implant device to introduce the bone graftmaterial but no specific device or method is disclosed.

SUMMARY

In accordance with one aspect of the present subject matter, a bonegraft material injector is provided comprising: an injector deviceincluding an elongated injector tube, an internal injector tube lumenextending through the injector tube and having a longitudinal axis, adistal injection aperture communicating with the lumen and a sideloading aperture for receiving a quantity of graft material into axialalignment with the lumen axis; and a graft material loader cooperativelyengageable with the side loading aperture and adapted to load a selectedquantity of graft material into axial alignment with the axis of theinjector tube lumen.

In another aspect a graft material injector device is providedcomprising: an elongated injector tube including an internal lumen; adistal injection aperture communicating with the injector tube internallumen and a side loading aperture communicating with the lumen; and acover associated with the side loading aperture and movable between aposition substantially closing the side loading aperture and a positionsubstantially opening the side loading aperture for loading graftmaterial into the internal lumen.

In a further aspect, as a graft material injector is providedcomprising: elongated injector assembly comprising an inner elongatedinjector tube and outer elongated cannula tube, the injector tubeincluding a proximal end portion and a distal end portion with a lumenextending therethrough; a handle secured to the proximal end portion ofthe injector tube; an injection aperture in the distal end portion ofthe injector tube; and an elongated side loading aperture in theinjector tube proximal of the injection aperture. The outer cannula issized to movably receive the injector tube therein, and the cannula andtube are relatively movable between a position in which the cannulasubstantially covers the side loading aperture to close the side loadingaperture and a position in which the cannula does not substantiallycover the side loading aperture to open the side-loading aperture forreceiving graft material into the injector tube lumen. The handleincludes an actuator engaged with the cannula for sliding the cannulabetween the positions substantially covering the side loading apertureand not substantially covering the side loading aperture.

In accordance with another aspect, a method is provided for injectinggraft material into a spine disc surgery site employing any of the aboveapparatus. More specifically, a method of injecting graft material intocooperative association with a spine disc implant is providedcomprising: introducing graft material into axial alignment with aninjector tube lumen through a side loading aperture; closing the sideloading aperture; positioning the distal end of the tube into thedesired position with respect to the implant; and moving a push rodthrough the lumen, thereby applying force to the graft material to forceit out the injection aperture and into association with the implant.

These and other aspects are found in the drawings hereof and thedetailed description below.

DETAILED DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view that shows one embodiment of a graftmaterial injector device.

FIG. 2 shows an exploded perspective view of graft injector device ofFIG. 1 .

FIG. 3 shows one embodiment of a possible application for the bone graftinjector of FIG. 1 .

FIG. 4 is a perspective view that shows one embodiment of a potentialloading hopper or graft material guide.

FIG. 5 shows one embodiment of a potential step one of the usage of thedevice.

FIG. 6 shows one embodiment of a potential step two of the usage of thedevice.

FIG. 7 shows one embodiment of a potential step two of the usage of thedevice.

FIG. 8 shows one embodiment of a potential step three of the usage ofthe device.

FIG. 9 shows one embodiment of a potential step four of the usage of thedevice.

FIG. 10 shows one embodiment of a potential step five of the usage ofthe device.

FIG. 11 is a perspective view of another embodiment of a graft materialinjector device/system.

FIG. 12 is a perspective of the graft material injector device of FIG.11 with components in different operative positions.

FIG. 13 is a perspective view of the graft material injector device ofFIG. 12 , with components in different operative positions.

FIG. 14 is a perspective view of the graft material injection device ofFIG. 11 taken from a different angle.

FIG. 15 is a perspective of the graft material injection device of FIG.11 with components in different operative positions.

DETAILED DESCRIPTION

FIGS. 1 and 2 depict one non-limiting example of a fusion graft materialinjection assembly or device generally at 20 embodying certain aspectsof the present subject matter. The illustrated injection device 20includes an elongated injector tube 22, that is axially relativelymovable with respect to an outer cannula 24, and a pusher 26 that isadvancable through the injector tube. The elongated injector tube has aninternal lumen extending between a proximal end opening 28 and a distalend opening 30. A side loading aperture illustrated in the form of anelongated slot 32 in the wall of the injector tube, is locatedpreferably but not exclusively in the distal end portion of the tubeproximal of the distal end opening 26. The distal tip of the injectortube could be square cut or beveled to facilitate entry into tighterlocations. A beveled tip could be oriented with respect to injector tubehandle 34 to be indicative to the surgeon of bevel opening direction.The tip could also have longitudinally oriented slits that could allowthe tube to collapse into tighter spaces and then expand when graftmaterial and pusher 26 are advanced through the injector tube lumen.Alternatively, the tip of the injector tube could be made of soft,pliable, non-atraumatic material. The injector tube, cannula and/orpusher may be made of any suitable material, such as stainless steel orrigid plastic.

Handle 34 is attached to the proximal end portion of the injector tube22 and is ergonomically configured for gripping ease. The handleincludes a proximal opening in axial alignment with the injector tubelumen to receive the pusher 26. The illustrated handle includes anaxially extending slot 36 that slidably receives an actuator, such as athumb tab 38, connected to the proximal end of cannula 24. Pusher 26includes an elongated rod or pin 40 having a closed distal end 42. Anergonomically shaped handle 44 is secured to a proximal end of the rod.

The cannula 24 and injector tube 22 are respectively sized for closefitting but still slidable engagement between the outer surface of theinjector tube and the inner lumen surface of the cannula. With thisarrangement, the cannula 24 defines, in effect, a cover that is movablerelative to the injector tube between (1) a substantially open oruncovered position that exposes the side aperture or elongated slot 32for loading graft material into the injector tube, and (2) asubstantially closed or covered position, where the cannula extends overand covers the slot 32 after graft material has been introduced into theslot.

Similarly, the injector tube lumen and the pusher rod 40 arerespectively sized for close fitting but relatively movable engagement.As explained herein, the pusher is used to push against graft materialthat has been loaded into the injector tube so as to apply force againstthe graft material and push it out the distal end opening 30 of theinjector tube. The relative close fit between the pusher rod 40 andinjector tube lumen prevents substantial amounts of graft material fromentering the spacing between the pusher rod distal end and the injectortube lumen when the pusher rod is advanced against graft material in theinjector tube lumen. The illustrated pusher 26 is configured forslidable moving of the pusher rod 40 within the injector tube lumen.However, the injector device may also be configured with a threadedengagement between the pusher 26 and injector tube or injector tubehandle such that rotation of the pusher handle 44, which could be in theform of a knob, advances the pusher rod within and along the injectortube lumen. Threaded engagement may provide greater control of injectionrate and/or volume and provide mechanical advantage over a slidingarrangement. As a further alternative, the pusher rod 40 could besignificantly smaller than the injector tube lumen, but terminate at alarger distal end such as a flexible, compliant polymeric orlow-friction tip that is closely sized relative to the injector tubelumen or in a state of compression therein so as to fully fill thelumen. Still another alternative is for the plunger distal tip to be ofmetal to provide a stiff rigid member that can be used as a graftmaterial tamp after the material is ejected from the distal end of theinjector tube.

While FIGS. 1 and 2 show a graft injection device or assembly 20 with aninjector tube 22 having side loading aperture in the form of a singleelongated slot 32, the injector tube may have more than one loadingaperture, and the aperture(s) may be of any suitable size or shape.Because bone graft material can include bone chips or particles ofrelatively large size that clog or impede delivery through the injectortube, the side loading aperture may also include or be in the form of afilter mesh or sieve that allows only graft material below a certainsize to pass into the injector tube lumen. Such a filter or sieve maytake any suitable configuration and may be in the form of pores or slitslaser cut through the side wall of the injector tube.

In the illustrated embodiment, the graft material device assembly mayoptionally include a guide or hopper 46 to assist in introducing graftmaterial into the injector tube. The guide may have any suitable shape.As illustrated in FIG. 4 , the guide is in the form of a funnel having afunnel wall 48 inclined toward a funnel outlet 50. More particularly, inthis non-exclusive embodiment the guide is elongated and has anelongated outlet substantially the same length at the elongated slot 32in the injector tube 22. The width of the outlet slot 50 in the guidemay be approximately the width of the elongated slot 32 or may have awider or narrower width. A narrower width may be selected to preventgraft particles exceeding a certain size from entering the injectortube. In this form, the elongated funnel outlet acts as a filter orsieve. Alternatively, a separate filter or sieve structure may belocated in the funnel outlet or otherwise mounted in the funnel tofilter or sieve the graft material. The size and profile of the guideaffords a stable, horizontal loading position for introducing graftmaterial into the injector tube. Variations of these features allow theguide and injector device to be adapted to change the angle oforientation with respect to the user, such as a 30° or 45° angle.

The illustrated guide 40 includes an injector tube guide in the form ofan opening or aperture 52 into which the injector tube is inserted forgraft material loading purposes. The opening 52 is located so as tocause alignment of the elongated slot 32 in the injector tube 22 withthe elongated outlet 50 in the funnel-shaped guide 46 when the injectortube is inserted into the aperture 52. More specifically, when theinjector tube is inserted into the aperture 52 of the funnel, theelongated slot 32 and elongated outlet 50 are in registration andcontact so that graft material can be forced, typically by manuallyapplied pressure, from the funnel into the injector tube. This providesa selected quantity or bolus of graft material in the injector tubehaving a length approximately that of the elongated slot 32 and adiameter or cross-sectional size of the injector tube lumen.

Steps for introducing graft material into the injector tube aregenerally illustrated in FIGS. 5-9 . FIG. 5 shows the graft injectionassembly in a loading configuration with the pusher 26 withdrawn to aposition where the distal end of pusher rod 40 is proximal of theelongated slot 32. Similarly, the thumb tab 38 of the cannula 24 is slidto the proximal end of handle slot 36. In this position, the cannula 24is retracted to substantially and preferably completely uncover theelongated slot 32 of the injection tube 22.

FIG. 6 depicts the injector assembly, in the loading configuration ofFIG. 5 , with the injector tube inserted into opening 52 of guide 46.This positions the elongated slot of the injector tube in registrationwith the elongated outlet 50 of the funnel shaped guide. (FIG. 7 isessentially similar to FIG. 6 .)

In the position of FIGS. 6 and 7 , graft material may be forced, bymanual pressure or tamp, from the funnel shaped guide, through theelongated outlet 50 and elongated injector tube slot 32, into theinjector tube lumen, filling it with a selected amount (e.g., about 1cc) of graft material axially positioned within the lumen.

The cannula 24 is then moved to the distal position in the handle slot36, as shown in FIG. 8 . This covers and closes the slot, readying theassembly for the next steps. The injector assembly is then withdrawnfrom the guide 46, with the pusher 26 still in the retracted position,as seen in FIG. 9 .

The distal end portion injection assembly is then introduced into thesurgical site where the graft material is required. One such surgicalsite may be the intradiscal space of the human spine. FIG. 3 shows suchan exemplary site, with an implant 54 located within a central area of adisc 56, from which the nucleus has been removed in preparation for theprocedure. An access tube 58 is shown extending through an accessopening in the disc annulus 60 and into a window 62 in the disc implant.The distal end of the injector tube 22 and cannula 24 may be insertedthrough the access tube or directly into the implant window (without anaccess tube), requiring only a small access opening in the tissue, suchas about 5 mm, that reduces risk of tissue trauma. When suitablylocated, the pusher 26 is advanced while the injector tube is heldfixed. The distal end of the pusher rod 40 engages and pushes the lengthof graft material along the distal end portion of the injector tube andout the distal end opening 30 into the central space within the implant.The travel of the pusher rod may be configured to optimize or indicateto the user the volume of graft material dispensed or the maximum volumedispensed. Of course, the illustrated implant is but one example, andthe fusion graft injection assembly or device as described herein may beused with other forms or types of implants or even without implants ifonly delivery of graft material to a surgical site is desired. Afterinjection, the assembly 20 may be withdrawn, and the loading andinjection procedure repeated until sufficient graft material has beendelivered to the surgical site.

An alternative embodiment of the fusion graft injection assembly ordevice is shown in FIGS. 11-15 , and generally identified by referencenumeral 80 in FIG. 11 . As illustrated, the assembly or device 80includes an injector tube and handle assembly 82 and pusher 84. Thepusher 84 is constructed essentially the same as the pusher 26 describedearlier, and includes a handle 86 and pusher rod 88, illustrated with aslightly enlarged blunt distal end 90.

The injector tube and handle assembly 82 includes elongated injectortube 92 and a handle or frame 94. In this embodiment the injector tube92 includes an internal lumen that extends between the handle 94 at theproximal end and a distal end opening 96. The handle 94 has a sideloading aperture 98 that is sized to receive a magazine 100 having aplurality of graft material chambers 102.

In the illustrated embodiment, the magazine 100 is illustrated in theform of a rotary cylinder with six graft material chambers disposedaround the cylinder and extending through the length of the cylinder soas to be open at each end or through chambers. The cylinder is rotatablewithin the handle 94 to allow each of the graft material chambers toaxially align with the axis of the injector tube lumen in an injectionposition. The proximal end of the handle 94, as in the prior embodiment,has a proximal opening 104 that is also axially aligned with theinjector tube lumen, for receiving the pusher rod 88.

In this arrangement the graft material chambers 102 may be pre-filledwith graft material and loaded into the handle 94 side loading opening98. Rotation of the magazine or cylinder brings one of the chambers intoaxial alignment with the injector tube lumen, allowing the pusher rod 88to be advanced through the handle proximal end opening 104, through thealigned graft chamber 102 and through the injector tube 92. In thismanner, graft material in the aligned chamber can be pushed by the forceof the pusher rod out of the chamber and along the injector tube lumen,exiting from the distal end opening 96 of the injector tube into thedesired location at the surgical site. The pusher rod may then beretracted proximal to the magazine 100, which can be rotated to alignanother graft material chamber with the injector tube lumen and thepusher rod again advanced to push another quantity or bolus of graftmaterial along the injector tube for delivery to the surgical site. Thiscan be repeated as needed to deliver the desired amount of graftmaterial without the need to withdraw the injector tube from thesurgical site to refill it.

Although the graft material magazine is illustrated as a cylinder, itmay be of any other suitable shape, such as a linear feed arrangementwhere the graft material chambers are disposed in a side by siderelationship for sequential positioning into an aligned injectionposition or one behind another, if so desired. Also, the magazine may beremovable from the handle to allow an emptied magazine to be refilledwith graft material or replaced with a full magazine without the need towithdraw the injector tube from the surgical site.

Referring back to the figures, FIG. 11 , shows the injection assemblywith the magazine 100 received within the handle side loading aperture98 and the pusher rod 88 advanced fully through the handle, the alignedgraft material chamber and the injector tube lumen. The distal end 90 ofthe pusher rod may be seen extending beyond the distal end of theinjector tube, where it may be used to tamp the graft material at thesurgical site.

FIG. 12 shows the assembly 80 in a loading position with the pusherretracted to a position where the pusher rod 88 is proximal of the sideloading aperture 98. This permits the magazine 100 to be inserted intothe side loading aperture 98 without interference from the pusher rod88.

FIG. 13 shows a position where the magazine 100 has been inserted in theside loading aperture 98 and the pusher is positioned for insertion intoproximal opening 104 in handle 94. FIG. 14 illustrates the pusher fullyadvanced through the handle, magazine and injector tube and extendingbeyond the distal end opening 96 of the injector tube. FIG. 15illustrates a more fully exploded view of the injector assembly 80, withthe magazine 100 completely removed from the side loading aperture 98.

Although the present disclosure is described in light of the illustratedembodiments, it is understood that this for the purposes illustrationand not limitation. Other applications, modifications or use of thesupport or distraction device may be made without departing for thescope of this invention, as set forth in the claims now or hereafterfiled.

The invention claimed is:
 1. A graft material injector comprising: anelongated injector tube including an internal lumen, a distal injectionaperture communicating with the internal lumen, and at least one loadingaperture communicating with the internal lumen, wherein the at least oneloading aperture is configured for loading graft material into theinternal lumen; and an outer cannula, wherein the outer cannula isconfigured to move relative to the elongated injector tube from a firstposition that exposes the at least one loading aperture to a secondposition that extends over the at least one loading aperture.
 2. Theinjector of claim 1 further comprising a guide adapted for cooperativeengagement with the elongated injector tube for guiding graft materialinto the at least one loading aperture.
 3. The injector of claim 1wherein the at least one loading aperture comprises an elongated slot inthe elongated injector tube proximal to the injection aperture.
 4. Theinjector of claim 3 further comprising a funnel configured for temporaryassociation with the elongated injector tube in registration with theelongated slot to guide graft material through the elongated slot andinto the elongated injector tube.
 5. The injector of claim 2 wherein theguide includes a funnel, wherein the guide is configured to position theat least one loading aperture in registration with an outlet of thefunnel to receive graft material from the guide into the internal lumen.6. The injector of claim 1 further comprising a handle secured to aproximal end of the injector tube, the handle including an actuatoroperable to move the outer cannula between the first position and thesecond position.
 7. The injector of claim 1 wherein the injectorincludes a proximal end aperture for receiving a pusher into theinternal lumen proximal to the at least one loading aperture.
 8. Theinjector of claim 1 wherein the elongated injector tube comprises morethan one loading aperture.
 9. A graft material injector comprising: aninjector tube, wherein the injector tube includes a proximal end portionand a distal end portion with a lumen extending therethrough, aninjection aperture in the distal end portion of the injector tube, andat least one loading aperture in the injector tube proximal to theinjection aperture; a cannula tube, wherein the cannula tube is sized toreceive the injector tube therein, the cannula tube being movablebetween a first position in which the cannula tube substantially coversthe at least one loading aperture and a second position in which thecannula tube does not substantially cover the at least one loadingaperture, wherein the at least one loading aperture is configured toreceive graft material into the lumen in the second position; and ahandle with an actuator engaged with the cannula tube for sliding thecannula tube between the first position and the second position.
 10. Theinjector of claim 9 further comprising a pusher rod sized for insertioninto an aperture of the proximal end portion of the injector tube toapply force to graft material in the lumen to force it out of theinjection aperture.
 11. The injector of claim 10 in which the cannulatube is sized for close fitting sliding engagement over the injectortube and the pusher rod is sized for close fitting sliding engagementwithin the lumen.
 12. The injector of claim 9 further comprising afunnel for engagement with the at least one loading aperture of theinjector tube to introduce graft material into the lumen.
 13. Theinjector of claim 9 wherein the injector tube comprises a push rodslidably received within the lumen.
 14. The injector of claim 12 whereinthe funnel is configured to prevent graft material exceeding a selectedsize from entering the lumen.
 15. The injector of claim 9 wherein theinjector tube comprises more than one loading aperture.
 16. A method ofinjecting graft material comprising: employing a graft material injectorof claim 1; inserting the graft material injector device into a graftmaterial loader; introducing graft material into the graft materialloader and into the internal lumen in alignment with a longitudinal axisof the injector tube; positioning the distal end of the injector tube tointroduce graft material into an implant; and moving a push rod throughthe internal lumen, thereby applying force to the graft material toforce it out of the distal injection aperture and into association withthe implant.
 17. The method of claim 16 further comprising placing theelongated injector tube in registration with a funnel and introducingthe graft material into the at least one loading aperture through thefunnel.
 18. The method of claim 16 further comprising substantiallycovering the at least one loading aperture after introduction of thegraft material.
 19. The method of claim 17 in which the at least oneloading aperture and the funnel each comprise an elongated opening toprovide for introduction of the graft material along a length of theelongated opening of the at least one loading aperture.
 20. The methodof claim 16 in which the graft material comprises bone graft material.